Horn for talking-machines.



T A. EDISONu HORN FOR TALKING MACHINES.

APPLICATION FILED MAY 24,1905. RENEWED JUNE 10, 1909.

Patented Dec. 21, 1909.

Inventor:

Llewellvn lark, Oran e L by.)

walls presenting. at all THOMAS A. EDISON,

0F LLEWELLYN PARK, ORANGE, NEW

JERSEY.

'LHORN FOR TALKING-MACHINES.

Application filed. May 24, 1905, Serial No. 261,651.

To all whom it may concern:

Be it known that I, THOMAS ALVA EDISON, a citizen of the United States, residing at l'lssex and State of'xew vented certain new and useful Improvements in Horns. for Tl alkinguuachines,

ll'case C.) of which the following is a description.

My invention relates to improvements in horns adapted for use with phonographs or other talking machines, and my objectis to roduct-a horn adapted particularly for recording nu-poses and by which superior results will be secured. ll'ith funnels as heretolore used. the walls thereof have been capable of vibrating themselves, and are reslumsive to. and vibrate sympr"hetically with. certain musical notes, to re production of iuharm'onic sounds. come recorded. tion or" the ich be tunnel walls. there is a consider- Furthermore. in such yibra- Specification of Letters Patent.

l l I l in the able loss of energy and a proportionate reduction in the cited on the diaphragm. resultinein further weakening and distortion the recorded sounds.

In carying my invention into effect, I make use of a funnel that is incapable of vibrating under the effect of ordinary sounds used in this art, by forming it with thick points of its longitudmal sec-tum. the shape of a truss. and eompoeer'l of some dead, non-metallie material. like plaster-ot-paris. coated With! a zard smooth varnish. I have, in fact, contructed a tunnel for the purpose, weighing as much as a ton. and whose mouth is several feet in diameter, and which gives no sym- Renewed June 10, 1909. Serial m. 501,422.

pathetic tones, due to its walls vibrating, and which absorbs scarcely any tion.

Reference is hereby made to the accompanying drawing which shows in axial sec tton a tunnel construoted in accordance with my invention. It will be observed that the wall or walls 1 of the funnel are of maximum thickness at a point between its ends and that the thickness decreases gradually toward each end so that a section thereof is in outline the form of an ordinary truss.

I prefer to make the tunnel of plasterot paris, since it may be readily cast, but obviously. other suitable materials may be made use of. The tunnel is supported in any suitable Way; and connection with the recording mechanism made preferably through the usual rubber section.

Having now described my invention, what l claim as new therein and desire to secure by Letters Patent is astollows:

1. A funnel for talking machines. the walls of which are of maiimum thickness at a point between its ends. substantially as set forth.

2. A tunnel for talking machines. which is of maximumthickness at a point intermediate its ends and whose thickness de- Patented Dec. 21, 1909.

energy from the f sound waves by having its mass set in vibrain the county of Jersey, have in til) 

